Embodiment of the present invention are related to a safety lockout to prevent rotation of an actuator when a selected distance between two portions of an actuated mechanism is exceeded. In particular, the safety lockout prevents rotation of the actuator shaft of a Full Thickness Resectioning Device (FTRD) by locking the shaft when the distance between the anvil and the stapling head of the FTRD exceeds a selected distance.
An FTRD is a device that is used to endoscopically remove lesions, growths or other tissue samples from a body cavity of a patient. Typically this cavity can be the rectum or a lower part of the intestine. During the operation of the device, a distal end of the FTRD is inserted in the cavity, and is oriented so that an opening formed in the distal end faces the tissue to be removed. Various devices can then be used to grasp the tissue and to partially pull it inside the FTRD. The surgeon operating the FTRD can then activate a stapler device disposed at the distal end of the FTRD, and staple the region surrounding the tissue sample so that it can be removed without excessive bleeding or the incision becoming too large.
Once the stapling is complete, the surgeon can activate the knife that cuts around the tissue, so the growth or lesion can be removed. The staples keep the surrounding tissue in position so the incision can heal more easily.
The stapler device is located in the head of the FTRD, and is generally activated by an actuating shaft operated by the surgeon from the proximate end of the FTRD. As the shaft rotates, staples are fired by the stapling mechanism, so that the surgeon can control where and when to fire the staple. The staple is fired from a stapling head portion of the stapler device, so that the prongs of the staple go through the tissue, and then are bent back by the anvil portion of the stapler device. The anvil bends and shapes the prongs of the staples, so that they hold the layers of tissue together.
While positioning the stapler device, the anvil and the stapling head can be moved axially relative to each other, so that the layers of tissue can be positioned in the gap between the two parts. The anvil is then moved closer to the stapling head to immobilize the tissue in a position suitable for stapling. If the anvil portion is not at the correct distance from the stapling head portion when the surgeon activates the stapler device, the staple""s prongs can be bent in an unsatisfactory shape, resulting in a less than ideal hold by the staple of the layers of tissue.
Conventional devices can have indicators to show to the surgeon whether the correct gap to form a satisfactory staple is reached, but it is up to the surgeon to check the gap before activating the stapler device. These systems also are subject to errors because of the distance between the stapler device and the gap indicator.
Exemplary embodiments of the present invention are directed to a safety lockout to prevent rotation of a rotary actuator of an FTRD that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.
To achieve these and other advantages and in accordance with the invention as embodied and broadly described, the invention is a safety lock-out to prevent rotation of a rotary actuator when an axial distance between a first and a second portion of an actuated mechanism exceeds a selected distance. The safety lock-out includes a shaft rotatably connected to the first portion, axially movable relative to the second portion, and defining a notch. A locking member adapted to lock the rotary actuator is included, that is movable between a locking position and an unlocked position. The locking member fits in the notch when in the locking position thus preventing rotation of the shaft. The device also includes a spring member urging the locking member in the locking position and an unlocking member adapted to urge the locking member in the unlocked position when the selected distance is not exceeded.
In another aspect, the invention is a locking mechanism to prevent rotation of an actuating shaft of a Full Thickness Resectioning Device, that includes a frame rotatably supporting the shaft and coupled to a stapling head of the Full Thickness Resectioning Device, and a yoke coupled to an anvil of the Full Thickness Resectioning Device, movable axially relative to the frame. The device also includes a locking member movable relative to the shaft between a locking position and an unlocked position, the locking member engaging a notch in the shaft to prevent rotation of the shaft when in the locking position. Also included is an unlocking member adapted to move the locking member to the unlocked position when an axial distance between the anvil and the stapling head is less than a selected distance.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed.